The present invention is directed to an operating mechanism for rotary shift initiation and subsequent transmission of a shifting movement in a multiple gear hub with a planetary gear mechanism for providing multiple transmission stages.
A multispeed hub typically consists of at least one planetary gear mechanism with at least one sun gear, planet gears meshing with this sun gear of at least one set of planetary gears as well as at least one ring gear in contact with the planet gears, which is arranged around a fixed axle. The torque is transmitted over a sprocket wheel to a driver and further over one of several transmission paths of the planetary gear mechanism to the hub shell or casing. The selective control of the corresponding transmission path is carried out through coupling points and clutch actuation points, which can be rotated or displaced relative to the axle. The choice of speed is performed with a switch in the handlebar region and is transmitted to the multispeed hub, e.g., mechanically by means of a linear movement of a control cable. The shift movement corresponding to the chosen speed is initiated in the internal hub. Sometimes an axle shifting device is used, which is located at the end of the hub axle or between the sprocket wheel and the frame dropout.
Shift movements can be initiated linearly by means of pushing or pulling elements, or rotationally by means of swinging or rotational elements. The shifting operation is generally guided from the outside over the axle, or guided through the axle or another standing component into the internal hub.
In EP 0 876 952 B1 a shift movement is introduced into the inside of the gear hub by means of an articulating mechanism which is mounted on the hub axle from its free end towards the inside. Thereby, an outer shift movement of a control cable, running vertically to the middle axle of the hub axle, is converted into a linear movement of a switch rod, which can move inside a central hole in the hub axle. A switching block, which is guided in a slot running obliquely to the middle axle of the hub axle and transversely through the hub axle, moves together with the switching rod. A switch socket working together with the switching block forms a clutch activation component. In the prior art there are also articulating mechanisms which are mounted on the end of the hub axle in the form of so-called “axle switching devices.” They are prone to defects because they protrude over the other components of the bicycle in the direction of the hub axle, and they are considered to be troublesome. Longitudinal bores and slots in axles are expensive to manufacture and lead to higher costs. Since no quick release can be used with a hub axle with a longitudinal bore, the assembly and disassembly of the gear hub on bicycle frames is only possible with tools.
In DE 10 2005 003 056 A1 a switching device with a linear switching movement is also shown. Thereby the switch cable is brought through an axially running opening in the bearing cone to an axial position between the sprocket wheel and the frame dropout, whereby the shift movement is transmitted to the hub gears. Thereby there is only a deflection of the shift movement from a direction perpendicular to the hub axle to a direction in the direction of the hub axle. A nut on the inner periphery of the bearing cone serves to receive the control cable, which also decreases friction on the control cable. A disadvantage to this solution is the fact that when the hub is mounted, a threaded end of the shift cable cannot be screwed in to the corresponding counterpart in the internal hub, or at least only with corresponding constructive arrangements.
A rotary initiation of the shift movement occurs in EP 0 679 569 B1 by means of a cable pulley mounted on the inside of the fixed cone, which is functionally connected with a large number of cam rings. A controlling movement causes a rotation of the cam rings, whereby each cam ring acts on a corresponding cam lever and whereby the pawl-controlled sun gears of the planet gear can be engaged or disengaged through further cam lever surfaces, catches and switch cam rods of the switching device. A determining problem of this switching device is that it consists of a whole series of individual parts and this is expensive to manufacture.
DE 10 2004 048 114 B4 describes the transfer of a rotary switching movement between the driver and the fixed cone. Hereby a switch casing rotationally mounted with regard to the hub axle is supported by a first ball bearing opposite the stationary fixed cone as well as by a second ball bearing opposite a rotating driver. The driver necessarily always rotates in the case of a driver movement, whereby frictional forces to the second ball bearing between the driver and the switch casing, which can drag the switch casing in one direction, cannot be completely excluded. This is disruptive with regard to setting the switch casing in the exact gear position.
In EP 0 383 350 the rotary movement of a cable reel is transferred to the internal hub via openings in the inner periphery of the fixed cone. The cross sections of the openings are executed in the form of segments of annuli around the hub axle, in which extensions of a gear shift casing move. Since the positions of the extensions for the various gears lie very close together, a very high degree of accuracy is required for the gear switching device, especially in the case of a large number of gears.
In DE 101 18 645 another example of an operating mechanism is shown.